WordNet (r) 3.0 (2006):

dairy farmer
    n 1: the owner or manager of a dairy [syn: dairyman, dairy
         farmer]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "dairy farmer":
   breaker, breeder, broncobuster, buckaroo, cattleman, cow keeper,
   cowman, dairyman, equerry, farrier, grazier, groom, horseshoer,
   hostler, rancher, ranchero, ranchman, sheepman, stableboy,
   stableman, stock raiser, stockbreeder, stockkeeper, stockman,
   tamer, trainer